The versatility of laser printers is well known. They can print forms, graphics and a rather limitless array of images. One important function is to print checks. Not just blank checks, but checks including payee, amount and the signature of a responsible party. When such financial documents are printed, there is an immediate need for security, including appropriate audit functions. Such printers are useful where many checks are written per day, such as in insurance companies, property management offices and financial institutions.
Check printers previously available have not had audit trail capability. Some highly complex and expensive printers have had a preprocessor, that is, have included microprocessor aspects with a printer. This added capability increased the versatility of the printer, without providing a high degree of internal security when involved in printing financial or negotiable documents.
When negotiable instruments such as checks are printed, they include magnetic ink character recognition (MICR) areas or lines. These lines of characters must be precisely formatted and printed to permit fast machine readability. It is also necessary that the MICR line be controlled so that nothing but MICR characters be printed in the area including the MICR line, called the "clear band."